166 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Of the ambulatory legs the first is feeble, reaching scarcely to 

 middle of propodus of second leg; second leg much larger but of 

 similar, shape, reaching middle of dactylus of third leg; third leg 

 very stout, with shorter dactylus than two preceding, the propodal 

 joint much wider at distal end than base of dactylus; fourth leg 

 shortest, not exceeding merus of third, its last 3 segments similar to 

 those of third. 



Description of inale. — Differs from female in smaller size, shorter 

 posterior margin, slightly projecting front, with deep median 

 groove, and longer antero-lateral marginal ridge. Abdomen wider 

 at the first 3 segments than the sternum on either side, and tapering 

 rapidly from base of third to middle of sixth segment, last segment 

 wider than long, evenl}^ rounded. 



Measurements. — Female (20860), length of carapace 4, width of 

 same 10, length of third leg about 10 mm. Male (Trinidad), length 

 of carapace 3.2, width of same 6.8 mm. 



Habitat. — ^Usually found commensal in leathery tubes of annelids 

 (Holmes). 



Range. — Puget Sound to San Diego, California. 



Material exomiined. — 



Puget Sound; 1907; 1 male (Stanford Univ.). 



Friday Harbor, Washington; July 1, 1916; Evelyn D. Way; in 

 tubes of Amphitrite; 4 females (49952). 



Trinidad, California ; June 2, 1896 ; S. J. Holmes, collector : 1 fe- 

 male, ovigerous, from calcareous tube of worm, cotype (20860). 



Trinidad, California; June 27, 1911; W. F. Thompson; 1 male, 

 4 females (3 ovig.) (Stanford Univ.). 



Mendocino, California; A. Agassiz; 1 female ovig. (1048, 

 M. C. Z.). 



Pacific Grove, California; 2 females y. (Stanford Univ.). 



Off Point Conception, California; kt. 34° 25' 25" N.: long. 120° 

 20' 00" W.; 31 fathoms; gy. S. brk. Sh.; Jan. 8, 1889; station 2908, 

 steamer Albatross; 1 female (24752). 



PINNIXA WEYMOUTHI, new species. 

 Plate 36, figs. 9 and 10. 



Pinnixa californiensis Weymouth, Leland Stanford Jr. Univ. Piibl.. Univ. 



ser. No. 4, 1910, p. 56 (part: young female from Pacific Grove). 

 Pinnixa faba Weymouth, Leland Stanford Jr. Univ. Publ., Univ. ser. No. 



4. 1910, p. 59, text-fig. 7 (pai't; not synonymy). 



Type-locality. — Monterey Bay, California ; 5 fathoms ; male holo- 

 type in Stanford University. 



Diagnosis. — Carapace narrow, sides subtruncate. Chelae pubes- 

 cent, thumb horizontal. Dactyli of legs slightly curved. 



